GEMPAK Configuration Information

Decoder/Data Entries for LDM pqact.conf

Sample decoder/data entries for LDM are provided in the GEMPAK distribution under the $NAWIPS/ldm/etc directory using a set of templates which will automatically create pqact.conf lines based on your $GEMTBL and $GEMPAK environmental variable settings.

Ensure your GEMPAK environmental variables are set (source the Gemenviron file if not already set), then run the script


This template script will produce a pqact.gempak file your current directory that you can edit and append to your pqact.conf file (or, you can have a separate pqact running from ldmd.conf just for the pqact.gempak file).

Typically, the $GEMDATA environmental variable set in the $NAWIPS/Gemenviron script will point to the data/gempak directory which resides under the LDM distribution. The environmental variables can be redefined to point to case studies or archive directories without any reconfiguration if the same directory structure as the real-time data is followed.

Create your data and log directories that LDM will expect under the ~ldm/data/gempak tree. The FILE actions from the LDM will create their own directory paths, however decoders which receive their data via PIPE should have their directory created first (decoders from NCEP do not automatically create their paths, most written at Unidata do create their output paths).

Displaying Satellite and NIDS data in NMAP, NSAT and Garp

Imagery is stored into a three tier tree structure which enables the Graphical User Interfaces to provide a hierachy of data menues. NIDS data can be directly filed from the LDM into this structure. Additionally, satellite imagery transmitted on the Unidata/Wisconsin IDD feedtype in AREA file format can be directly filed into the data hierarchy using the ldm-mcidas program pnga2area. Pattern-action examples for storing these products are available in the pqact.conf examples above.

Configuring the LDM to store files for NALARM

Nalarm is a desktop GUI that automatically notifies you when a bulletin you are interested in arrives, and provides a text window for browsing the content of the product. Each user can have their own set of files to be viewed in Nalarm.

To configure Nalarm for your system:

  1. Decide where alarm bulletins from the LDM will be written. This directory will be defined using the AFOS_ALARMS environmental valiable defined in the Gemenviron file. Typically, AFOS_ALARMS is defined as $GEMDATA/alarms.

  2. Create pqact.conf entries to file desired bulletins into user directories under $GEMDATA/alarms. For example, if the user "frodo" wants to be notified of all tornado warnings issued, the following pqact.conf entry could be used:

    WMO	^(......) (....) ([0-3][0-9])([0-2][0-9])([0-6][0-9]).*/p(TOR.*)
    FILE     data/gempak/alarms/frodo/(\3:yyyy)(\3:mm)\3\4\5_\6.\1_\2

  3. The LDM will automatically create the data/gempak/alarms/frodo directory when a product arrives if it does not already exist. You should give the user "frodo" write access to that directory as well so that he can delete bulletins after he reads them. It is useful to automaticall scour these directories to several days accumulation (such as with the scour.conf configuration for "ldmadmin scour") to keep these directories from accumulating too many messages if the user is deleting them himself.

  4. Nalarm will look for files for the current user under $AFOS_ALARMS/~frodo.

  5. In order for "frodo" to be notified when bulletins arrive, he should launch Nalarm (available from the NTL bar, or the command line), A small window will be created which can be placed in a convenient area of the desktop.

  6. When a new file appears in the user's alarm directory, the New Product panel of the Nalarm window will flash red. Clicking on the New Product icon will launch a browser showing available products in the top window. Clicking on a product name will display the text in the bottom of the window.

  7. The bulletin can be printed or deleted from the browser.

  8. Clicking Exit closes the browser down, the allarm button will remain on the desktop until the Nalarm window is exited.

  9. If a $AFOS_ALARMS/~frodo directory does not exist, the GUI will attempt to look in $AFOS_ALARMS/nawips if it exists.

Keeping up to date with NOAAPORT changes

Realtime data stream users can keep informed about NOAAPORT data stream changes through the nws-changes email list, as well as through the administrative messages broadcast on NOAAPORT. Here is a sample pqact.conf entry to mail these messages automatically from your LDM:

WMO ^(ADMN[0-68]. ....|ADMN9[^9] ....|ADMN7[^5] ....|NOXX.. ....|NOUS[^456789]. ....|NOUS[4678]. (KWNO|KWBC|KNCF)|NOUS9[^7] ....) PIPE -strip -close /usr/bin/mailx -s "ADMIN NOTICE \1"

Just replace the template email address with one you wish to receive notifications with.

Generating Nmeta files for NTRANS

The Ntrans program utilizes an environmental variable in Gemenviron called $NTRANS_META which specifies the top of your metafile tree. Ntrans will create selection buttons withing the select model widget for each subdirectory it finds in $NTRANS_META. Clicking on a button within select model will present all the file names located in that directory.

For example, if you generate meta files for the ETA model, and store these in the directory $NTRANS_META/eta, selecting the ETA button will display the names of your meta files in that directory. For more information see Ntrans in the tutorial.

Configuring the Garp_defaults file

Garp uses the file $GARPHOME/config/Garp_defaults to define the names and locations of the various gempak data sets it can plot. These defaults are currently set to use the file suffixes demonstrated in the decoders examples for pqact.conf. Additionally, the directories are compatible with those defined in Gemenviron ($MODEL for gridded data sets, $SAT for the AREA, $RAD for Nids image tree, $GEMDATA/surface for METAR, $GEMDATA/syn for land synoptic, $GEMDATA/ship for ship synoptic, $GEMDATA/upperair for radiosonde data, $GEMDATA/profiler for profiler data).

The grid functions which may be defined for quick access are defined in files called FDFs. You may add additional FDF functions or categories. If you add a new subdirectory for a separate category, you must add this directory to the Garp_defaults file. FDF files contain parameters similar to those you typically specify in the GD programs within GEMPAK.